I don't think it has to be that fancy....For smaller vehicles to be able to tow heavier trailers, it would take sophisticated active suspensions. If they were set up to handle 1000-1500 pounds of hitch weight, they would be nearly uncontrollable when not towing. For the vehicle to "ride nice" and hold the road when not towing,they need supple suspensions ....... supple suspensions do not lend themselves to high hitch weights. Not to mention what a short wheelbase does to towing handling.....
The current Jeep Grand Cherokee is rated to tow 6200-7200lbs. Similar engine, trans, vehicle size, wheelbase, payload, and vehicle weight.
That is nearly a 2x improvement on what we see with the JLU platform, and inline with the JT program.